Anvil



c. M CURRY ANVIL Filed OCT.. '7l 1918 alu Patented July 8, 1924,

umso STATES? onAiaLns` 1v1. cURRYgO-F TULSA, oKLAHoMA.

VANV'IL.

Appuction mea october 7', 191s. serial No. 257,185.

To all whom it may concern.'

Be it Iknown that I, CHARLES M. CURRY, a citizen of', the United States, residing atV Tulsa, inthe county of rlulsa and State of Oklahoma, have invented" certain new and useful Improvements in Anvils, Of which the following is a specilication. Y

My inventionV relates to an improvement in anvils, and has to do 4,with the art of driving a hollow Vmetal rivet through metal, or metal and other material, to be riveted, without the necessity of punching a preliminary hole therefor, and the final upsetting of the rivet; and in other words it consists in` forcing the yrivet initially through the parts to be riveted and ulti-` mately upsetting it. Y l

Heretofore attempts have been madefto force a hollow rivet directly through sheet-V metal vwithout previouslyv punching a hole, but'without success. Y y

My invention is a demonstrated success,

' andit comprises an anvil or die fashioned.

Yon its working face to receivev theV parts to be riveted, and having an annularrecess therein of definite depth and width with respect to the thickness of the metal to be riveted, over which recess the pressure of the rivet is applied against the sheetmetal, which latter can be stretched just so far and no further, and when the maximum point of tension is reached under the pressure ofthe rivety it will part, the metal to be stretched being forced down into the' annular recess where thek metal is allowed to flow to its maximum vand part 'under the pressure of the rivet, after which the emerging .end of the rivet is upset.

In the accompanying drawings: y

Figure 1 is an enlarged vertical sectionah view through the anvil;

Figure 2 is a plan View;

Figures 3, l and 5 show different posi-V tions of the rivet in its progress through the metal parts being riveted;

Figures 6 and '7 are sections showing the embedding of the head and opposite end of the rivet respectively.

rlhe numeral l'represents the anvil. An annular recess 2 is formed in the upper or working face of the anvil, leaving the central stud 8 with a conical base and the outer surface 4 Hush or in the same plane with the outer surface of the stud. n

While the width and depth of the recess 2 may be varied, and in fact are intended to ybe Vfor diiierent purposes, nevertheless both its width and dept-h have some definite relation to the thickness of themetal 'orparts to be riveted, and, generally speaking, thedepth of this 'recess is approximately four times the thickness of the metal being riveted, and it is desirable that the surface of the anvil.

Referring to Fig. 1,."the width of the recess Vor distance between the points a and jb represents theiquantity vof metal to be dealt with, and a piece of metal `corres'pkondkouter surface of the recess should beat or l approximately at right-angles to the outer ing Vin area to the distanceffrompoint to b can be stretched just so far and no further, and, when the maximum` point of.

tension due to the pressure vof the rivet in penetrating the metal is reached, the sheetmetal will part. vThe sheet-metal to be stretched must beY made to pass down into not'pass through. Again, if Athe annular 7 recess 2 is not sufficiently deepto allow the metal to flow to its maximum and part, it would not rivet. more than others, and some are thicker than others,H and it is therefore evident that the width of the recess or distance from a to b must be determined by the metal and its thickness, so that not only is the Vrelative depth of the recess which must aiford abundant clearance for the iow ofthe metal aroundthe rivet and the rupsetting a factor, but alsoftlie distance across from a toY b is of onlyr secondary importancethereto..

By following the action 'illustrated in Figs. 3, 4 and 5, it will be noticed that the part of the metal 6 between the outer part of the rivet and the outer part of the annular recess in the anvil is stretched. This shows what is termed the flow of the metal, that'is to Vsay all metal under such conditions flows, and that explains why it is possible to force the rivet through it. Consequently if the outer edge of the annular recess in the anvil is not at rightangles or approximately at right-angles to the surface of the outer or top plane of the anvil, the metal owing down around the outer edge of the rivet would come into Somev metals will liow contact with the curved surface. thus stop,- ping the: flow of the metal, and the rivet would would not penetrate it. As soon as it has reached its maximum flow, the metal under tension gives way, andV the rivet passes through. Y

In Figs. l and 5, this iow is clearly shown at 6; in other words, it is only possible to stretch the metal to be riveted so far, and thenA it parts. The anvilV isv only a means for stretching. themetal to a4 point to make a hole and allow the rivet to pass through,v

upsetting it. The art ofl penetrationv or insertion of the rivet is in effect one act, andthe upsetting of the rivet is another and entirely distinct therefrom; in other words, making the holeis` one act, and fora. ing the rivet tlntough` that holel and upsetting it, is another. y,

|Ilhe numeral 8. represents the punch, for forcing theA rivet through sheetfmetal or other. material.

In Figs. Gand 7, I have simply illustrated different effects of punching the rivets i through.; inl onethe head is shown countersunk; and 1n the other the opposite end is similarlyy illustrated.

It will be noticed, as aresultant of the metal fiow and the nal rupture, a blank remains onl the end of`r the stud, which is forced by the. latter asA if: by a punch into the center ofA the hollow rivet, giving the rivet in, effect a, more. or less solid center,

thus adding. materially toits strength andy rigidity as a. fastening device.

My inventionhas nothing. todo with the feeding. of the rivets, whiclris easily accomplished;v and ithas nothing to d o with. the

the working end or face of said anvilor die having an annular curved groove or recess therein', leaving a tapering central stud and a surrounding surface, the outer ends of which are substantially Hat and flush with each other, the external diameter of the outer end of the stud and the internal diameter of the tubular rivet to be upset being approximately the same, whereby to cause a cheering action between the stud and rivet uponl the material to be riveted, thereby causing the rivet first to. cut its own way through the material and then havev its cutting end upset.

2. An anvilv or die for forcing tubular rivets through sheet-metal andupsettingthe same, comprisingy an inner central stud havingI a flat upper surface of substantial area,

,an 4outer concentric bearing surface in the same plane as. theflat upper surface of the central stud, spaced therefrom by a con,- centric recess formed between the surfaces,

the recess in cross-section being,substantiallyl greater than a semi-circumference 1n depth,

and forming a shoulder with-the outer bearing surface upon which the4 sheet-metaly is bent, and. betweeny which shoulder and the rivet sheet-metal mayl flow beyondl the: breaking point into the recess, and the bottom of the recess being so formed. asto upset such rivet.

3. An anvil. or die for forcing tubular rivetsthrough sheet-metal and upsetting the.

into the recess, and thebottom of the recessy being so formed. asto upset such, rivet.

In testimony whereof I aiiix my signature.

cHARLEs M. cURnY. 

